The Society of Interventional Radiology (SIR) is an American national organization of physicians, scientists and allied health professionals dedicated to improving public health through the use of minimally invasive, image-guided therapeutic interventions for disease management.

In April 2002, the name was changed to Society of Interventional Radiology in order to emphasise the expanding role of interventional radiology that is no longer limited to the cardiovascular system.

The society comprises about 8,000 members (March 2023): including practicing physicians, trainees, scientists and clinical associates, such as physician assistants, nurse practitioners, radiologic technologists and paramedical professionals.

SIRPAC is funded through donations from SIR members, and uses these funds to support political candidates who have demonstrated a commitment to policies that promote patient access to interventional radiology services and advance the specialty.

During the 2022 election cycle, SIRPAC donated $135,682 to candidates (65.65% to Democrats, 34.35% to Republicans) and raised more than $180,000 from members.